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�00 <br /> "TWINING <br /> CONCRETE INSIGHT <br /> Morrison Quarry Rock Petrography Page 21 <br /> 4.3 Rock Sample HDR-002 (225.0-225.6): Biotite Gneiss <br /> Received Condition <br /> The sample is a rock fragment that measures —60 mm (2 % in.) in diameter and <br /> —135-210 mm (5 % - 8 '/4in.) in length (Figure 4.3a). Both ends of the core are fractured <br /> surfaces and the side surfaces are rough cored surfaces. The core was received intact in one <br /> piece. No weathered surfaces are present. <br /> Polished Slab <br /> The rock on the polished surface is pale pink and bluish-gray to bluish-black (Munsell Soil <br /> Color 2.5YR 5-6/2 and GLEY 2 2.5-4/5PB) and predominantly consists of quartz, orthoclase <br /> feldspar, plagioclase feldspar, and biotite, with minor amounts of chlorite (Figure 4.3b, <br /> Figure 4.3c). The rock sample exhibits a well developed gneissose structure with alternating <br /> felsic (quartz, feldspar) and darker mineral layers (biotite, chlorite). Gneissic layers measure <br /> up to —6 mm (1/4 in.) thick and are laterally discontinuous. Quartz and feldspar grains are <br /> medium grained and measure up to —2 mm (80 mil) in diameter. The rock sample is hard and <br /> competent, and the Mohs hardness of the sample is 3.5-4+. <br /> Thin Section <br /> The rock is a high-grade metamorphic rock classified as a biotite gneiss (Figure 4.3d, <br /> Figure 4.3e). The sample consists of major amounts (>10%) of medium grained quartz, <br /> orthoclase feldspar, plagioclase feldspar, and biotite measuring up to —2 mm (80 mil) in <br /> diameter, and minor amounts (1-10%) of chlorite. A trace amount (<1%) of opaque minerals <br /> are observed. Quartz and felspar grains are subhedral to anhedral in shape and occur as <br /> segregated layers. Biotite and chlorite grains are elongated in shape and exhibit a preferred <br /> orientation. <br /> Sample HDR-002(225.0-225.6): Biotite Gneis <br /> Major minerals Quartz(-40-50%),feldspar(-30-40%),biotite(-20-30%) <br /> (10-100%by volume of rock) <br /> Minor minerals Chlorite(-1-5%) <br /> (1-10%by volume of rock) <br /> Trace minerals Opaque minerals <br /> (<1/o by volume of rock) <br /> Report No. 227893.d 22 November 2022 <br />